My daughter is 4 months old, 3 months corrected. And she is starting to roll. I have her in a sleeveless sleep sack now and early this morning I find her on her belly awake and having trouble getting back over but keeping silent. I freaked lucky got to her. I’m now scared I will accidentally find her like that again and sids will happen? Is it safe if she rolled that way herself and stays that way?

Red Nose recommendations are to “always place baby on back for sleep” not baby must always sleep on their back.
https://rednose.org.au/article/red-nose-safe-sleeping-recommendations

Most babies will be rolling over by 4- 5 months. Some earlier, some later.
This is very normal as babies grow & become stronger.
Many babies then prefer to sleep on their side or tummy.
This is not something that needs to be stopped. It is important to make the “new” environment as safe as possible.
https://rednose.org.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-over  (please read this article)

Is the “sleeveless sleep sack” one with baby’s arms contained (like a swaddle)?
If so, she needs to have her arms free, not contained in swaddle sack. A safe sleeping bag (with arms out) is best option now.

If she is in a bassinet, we would recommend you move her to a cot.
Babies need arms free & the space of a cot to roll well & safely.
Ensure mattress is firm & flat & nothing soft or loose in her cot.
Continue to always place your baby on back for sleep.

How does she go with tummy time when awake?
Increasing tummy time when awake is important to build upper body strength to roll well (both ways)
Is she rolling from tummy to back during tummy time, holding her head well &/or reaching for toys?

Once baby is rolling well, both ways, still place her on the back for sleep & allow her to find her position of comfort.
(see article linked above)

In the meantime, if you see her rolled to side or tummy, gently roll her back.
However, parents are not expected to sit up all night watching baby. This is not achievable.